The book takes the perspective of soldiers with the Group of Soviet Forces in East Germany as they prepare to launch an invasion of West Germany. Soviet General Mikhail Malinsky, commander of the First Western Front, discusses the upcoming invasion with other Soviet leaders. The plans call for a simultaneous thrust on three fronts: across the North German Plain, through the Fulda Gap, and across Bavaria. NATO commanders are to be bluffed into thinking the main assault will come at the Fulda Gap, but the main effort will be on the North German Plain, led by Malinsky. Airborne forces will be dropped deep into West Germany to disrupt the NATO rearguard.

The Soviet commanders believe that if Soviet forces are deep inside West Germany in three days, NATO will not be able to use its nuclear weapons to blunt the advance. A Soviet propaganda film about the destruction of Lueneberg (carefully produced at a Moscow studio) will also add psychological shock to the West Germans.

When the invasion begins, the Soviets advance quickly, bypassing strong points whenever possible. The successful capture of a NATO command post and a Soviet tank company's capture and shepherding of a German refugee convoy outside Hildesheim adds to the speed of movement. The West German forces positioned on the inter-German border are gradually cut off from their resupply lines, while a unit trapped in the Cuxhaven peninsula fights to the last man. Deprived of reconnaissance assets, however, Malinsky worries that the U.S. Army forces based near the Fulda Gap will come to the aid of the British, Dutch, and West German forces that he faces.

Day three of the war finds the Soviets nearing the industrial Ruhr valley. Hoping to forestall a complete West German collapse, remaining NATO forces in the north, joined by the strong and relatively unbloodied U.S. Army from the south, hit Malinsky's First Western Front from all sides. It is not enough. Before the NATO counterattack has a chance to succeed, the West German government asks the USSR for a cease-fire, and in the aftermath, the Soviet Army occupies all of Germany east of the Rhine.